title: Oxidized multiwalled carbon nanotubes for quantitative determination of cationic surfactants in water samples using atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry.
abstract: Oxidized multiwalled carbon nanotubes (O-MWCNT) are used as preconcentrating probes for the quantitative determination of cationic surfactants (CS(+)) in water samples using atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry (AP-MALDI-MS). The method is based on the electrostatic interactions of positively charged CS(+) with the negatively charged O-MWCNT for the preconcentration and isolation of analytes from sample solutions. The O-MWCNT/AP-MALDI-MS is performed for the determination of CS(+) in river- and waste-water samples. The optimum extraction efficiency of CS(+) is observed for 7 min of contact time at 1.0 mg dosage of O-MWCNT at pH 7.0. The acceptable relative recovery percentage in water sample is obtained in the range 90.5-97.8% with relative standard deviation (R.S.D.)<14.5%. The results suggested that the newly proposed method is rapid, accurate and effective and could be successfully applied for the enrichment and quantitative determination of CS(+) in water samples.
authors.affiliation: Department of Chemistry, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
authors.forename: Kamlesh
authors.initials: K
authors.lastname: Shrivas
authors.forename: Hui-Fen
authors.initials: HF
authors.lastname: Wu